Concern is mounting over the well-being of jailed opposition figures in Belarus amid reports of prison abuse, including threats of torture, rape, and murder.

Human rights campaigners in Belarus and abroad are calling on Minsk to end what they describe as the mistreatment and intimidation of inmates held on politically motivated charges, in particular opposition figures Zmitser Dashkevich and Ales Byalyatski.

"The situation with political prisoners has been quite dire. People held on politically motivated charges have been singled out in detention," says Human Rights Watch's Yulia Gorbunova.

Human Rights Watch accused Belarusian authorities on October 2 of "retaliating against their critics even after they are thrown in jail" and urged Belarus to immediately investigate all instances of mistreatment.

The global rights group says ill-treatment of political detainees appears to be on the rise in Belarus, with inmates increasingly facing verbal abuse, unfair punishments, and psychological pressure.

Gorbunova says Dashkevich has also been subjected to alarming threats from prison staff, including "threats of rape by other inmates and of physical violence, up to murder. He's also subjected to verbal abuse and he's facing a lot of arbitrary punishment, including restriction on meetings with his relatives."

Platform, a Belarusian rights group monitoring the treatment of prisoners, sounded the alarm last week by filing a complaint to the United Nations' special rapporteur on torture.

Increasing Pressure

Rights groups have denounced a rollback on freedom since the reelection of authoritarian President Alyaksandr Lukashenka in December 2010.

The election sparked massive street protests that led to the arrest of almost 700 people and the sentencing of dozens of protesters to jail terms.

Rights groups accuse Belarusian authorities of intensifying their crackdown on dissent over the past two years, detaining opposition activists, disbarring lawyers who defend detainees and intimidating rights campaigners and journalists.

Ales Byalyatski has been barred from seeing his family since May and is constantly punished.

A dozen opposition activists detained during or since the postelection protests still remain in detention.

These include Ales Byalyatski, the head of the Belarusian human rights center Vyasna, sentenced in November 2011 to 4 1/2 years in prison on charges of tax evasion; former presidential candidate Mikalay Statkevich, jailed for six years in May 2011 for "organizing mass disturbances" following Lukashenka's reelection; and Dashkevich, the leader of the youth opposition movement Young Front, convicted to two years in March 2011 for hooliganism after an alleged brawl on the eve of the presidential election.

'Time To Clamp Down'

Dashkevich is barred from family visits and has spent months in an isolated cell. In August, he was sentenced to an additional year in prison on charges of repeatedly disobeying the prison administration.

Relatives and friends are worried about his health, which they say has been deteriorating in recent months.

On September 21, two days after being transferred to a new penal colony in the southwestern city of Mazyr, Dashkevich declared a hunger strike to protest what he said was "inhumane treatment" at the prison.

His fiancee, Nasta Palazhanka, has filed a request asking prosecutors to investigate the alleged abuse by prison authorities in Mazyr.

"As soon as he arrived there, attitudes toward him changed completely. Apparently they decided that it was time to clamp down on him, to further bear down on him. There were constant insults, insults to his dignity, his human dignity," she says.

"In order to put an end to this campaign of harassment, Dzmitser went on a hunger strike. So of course I'm worried about him, because of this hunger strike and this treatment of him in Mazyr, and because of the whole system of pressure that is bearing down on him."

Palazhanka says she has not seen Dashkevich since April 2011.

Constant Punishments

Human Rights Watch says Byalyatski has been barred from seeing his relatives since May. In June, he was declared a "repeated violator" of prison rules, making him ineligible for amnesty.

Activists say Byalyatski is subjected to routine reprimands, including restrictions on his mealtimes and on permissions to receive parcels and visits. Other prisoners are allegedly prohibited from talking to him.

Byalyatski, Dashkevich, Statkevich, and several other Belarusian detainees have been declared prisoners of conscience by Amnesty International.

Written in Prague by Claire Bigg based on reporting by Aleh Hruzdzilovich in Minsk